The Pro Cinema LS10000 has the deepest black levels I've seen yet from Epson. From a practical standpoint it does better than Epson's less expensive UB series, which set the standard for under $4000 projectors several years ago, and those haven't been bested yet for under that price point, although there's serious competition.
I do not believe that this Epson is a match for the projectors with the very best black levels out there. I'm talking about the $8000 and $12000 JVCs, they remain the champs, but, that said, the black level performance is better than the Sony HW55ES and JVC X35, and even Sony's $15K VW600ES true 4K machine. How it stacks up against Sony's $27,000 VPL-VW1100ES is a good question, one I expect to answer soon as I'm expecting that Sony to arrive shortly after the Cedia show (9/2014), so I'll be able to do side by side comparisons. Editor's note, the update includes a direct comparison with Sony's flagship 4K projector the VW1100ES.
As I have always said, great black levels have been the "holy grail" of home theater performance. That's the difference between good $2000 projectors (or good $5000 projectors...) and great ones. But I've also said that once black levels achieve a certain level of excellence, while even better is always desirable, that's the point where other aspects of the projector become more important than further black level improvement.
When I reviewed the Sony VW600ES I said black levels were very good, but not truly great (for $15,000), yet, thanks to true 4K projection the projector earned our top honors in our 2014 Best Home Theater Projectors report. Why? outstanding color, amazing sharpness, and so on. With the Epson LS10000 I believe we have a projector here with better black level performance on those dark scenes (where it's fully appreciated) than that Sony, so that's pretty darn good! Ultimately though since there really isn't a dynamic iris, it means that black level performance on brighter scenes is also better. Of course, immediately below, we've cued up the Bond night train scene image from several top projectors for comparison. On other images such as the starship from The Fifth Element, the Epson does even better compared to the competition using dynamic irises, because those other projectors find enough brightness that the iris does stop down, but not all the way.